In the field of printing technology, different cylinders of printing machines have respective coatings, which serve certain distinct functions. For instance, in the case of electrographic printing, the image generation cylinder, or illustration drum, are often coated with an organic photoconductor on which the latent images are formed. A blanket cylinder, which is used in particular during offset printing and also in the capacity of a transfer drum in toner-based digital printing, and the fuser roller for fixing the print toner on the impression material at another printing pace in the printing machine, are usually coated with an elastomer.
A significant aspect in the avoidance of image degeneration and for the assurance of the printing result, for instance in electrophotographic printing, is the formation of the surface of the illustration drum or the transfer drum with the highest precision. On the basis of wear and tear at the surface of the illustration drum, these drums, as well as transfer drums and fuser rollers are replaced from time to time. The aforementioned high-precision drums and the surface quality maintenance requirements connected to the substitution of new/replacement surfaces are, however, costly and time-consuming.
The surface of transfer drums are known as thin cuffs, also called sleeves, and are self-supporting, and are assembled on a core which serves as carrier. If the surface has worn out, only the coating or the coating together with the thin cuff are substituted where the coating is connected. The carrier of the coating and the coating with the thin cuff or sleeve may continue to be used. Demands on the coating involve minor wall thickness of the coating and low production costs. Depending on the particular cylinder use, further demands may involve an even electrical and/or thermal conductivity, photoconductivity, or an equal wall hardness and elasticity along the coating. The foregoing demands are met in which multiple layer technologies are applied which are, however, disadvantageous since these require a time-consuming and expensive production process. Multiple layers are arranged one after the other in order to form a coating in the known process whereby the layers are each cooled down or hardened before applying the next layer, which results in a long production time.